Estimating Traffic Emissions Using Demographic and Socio-Economic Variables in 18 Chilean Urban Areas

A macro-scale methodology for vehicle emissions estimation is described. The methodology is based on both correlations between activity level and PM, CO, THC and NO _x vehicle emissions and relationships between demographic and socio-economic variables and transportation activity level. First, pollutant emissions were correlated with transportation activity, expressed as vehicle-km/year, using existing data collected from mobile sources emission inventories in nine urban cities of Chile. Second, demographic and socio-economic variables were pre-selected from those that could intuitively be correlated with vehicle activity level and considering the data availability. Using the individual R ² correlation coefficient as variable selection criterion, population, the number of vehicles, fuel consumption, gross domestic product, average family incomes and road kilometers were finally chosen. A different set of explicative variables was considered for different vehicle categories, based on the selection criterion above mentioned. Then, correlation functions between these variables and transport activity were obtained by non-linear Gauss–Newton least square method. This methodology was applied to eighteen provinces of the country obtaining total annual emission for mobile sources, divided into six main vehicles categories.     

The Capability Approach and Fuzzy Poverty Measures: An Application to the South African Context

One way of making the capability approach (CA) operational uses fuzzy poverty measures. In this paper, we present a new approach to applying these measures in the South African context using responses to a questionnaire on ‘The Essentials of Life’ in conjunction with a methodology for dealing with the vagueness of poverty. Our results suggest very low cut-offs for people or households to classify as definitely poor for some social indicators. These cut-offs are far lower than those Klasen used in his application of the CA. The attempt to apply the CA using Cheli and Lemmi’s ‘totally fuzzy and relative’ poverty measure in conjunction with our approach to specifying cut-offs can lead to incoherence. This measure can, nonetheless, be useful when social indicators have a ‘relativist component’. While the Cerioli and Zani measure does not lead to such incoherence, it also has a serious weakness.     

亚健康"青睐"知识分子吗? --中国知识分子健康研究报告之二

本文研究了中年高级知识分子的亚健康状况及其影响因素.本文通过对北京市中关村科技园区海淀园及北京市所属企事业单位共计2500名中年高级知识分子以及505名普通人群的调查资料进行对比分析,发现亚健康状态在中年高级知识分子与普通人群间并没有显著性差异,从而得出中年高级知识分子并不是亚健康的高发人群的结论.同时对造成中年高级知识分子亚健康状态的影响因素进行了分析,结果表明中年高级知识分子的亚健康状态主要是由于生活压力和工作压力过大,缺乏体育锻炼,以及与不能落实体检制度和休假制度有关.     

The educational attainment of second-generation immigrants in The Netherland

Since the mid-1960s the Netherlands has had a positive net immigration, mainly because of man power recruitment from Turkey and Morocco and immigration from the former Dutch colony of Surinam. Immigrants havea weak labor market position, which is related to their educational leveland language skills. Children and grandchildren of immigrants are expected to have a better chance of integration into Dutch society. In this paper we investigate whether this is true with respect to the educational attainment of second-generation immigrants from Turkey, Morocco, Surinam and the Dutch Antilles.The authors thank an anonymous referee and both editors for helpful comments. Responsible editors: David Card and Christoph M. Schmidt.     

Erosion of Advantage: Decomposing Differences in Infant Mortality Rates Among Older Non-Hispanic White and Mexican-Origin Mothers

We build on findings from recent research showing an erosion of infant survival advantage in the Mexican-origin population relative to non-Hispanic whites at older maternal ages, with patterns that differ by nativity. This runs counter to the well-documented Hispanic infant mortality paradox and suggests that weathering and/or other negative health selection mechanisms may contribute to increasing disadvantage at older maternal ages. Using the National Center for Health Statistics (NCHS) cohort-linked birth and infant death files, we decompose the difference in Mexican-origin non-Hispanic white infant mortality at older maternal ages to better understand the contribution of selected medical and social risk factors to components of the difference. We find differences in the distribution and effects of risk factors across the three populations of interest. The infant mortality rate (IMR) gap between Mexican-origin women and non-Hispanic whites can be attributed to numerous offsetting factors, with inadequate prenatal care standing out as a major contributor to the IMR difference. Equalizing access to and utilization of prenatal care may provide one possible route to closing the IMR gap at older maternal ages.     

Selection,selection, selection: the impact of return migration

The evidence on the impact of return migration on the sending country is rather sparse, though growing. The contribution of this paper is in addressing various selectivity problems while quantifying the impact of return migration on wages of returnees using non-experimental data. Using Egyptian household-level survey data, I estimate the wages of return migrants controlling for several selectivity biases arising from emigration choice, return migration choice, labor force participation choice, and occupational choice following return. The findings provide strong evidence that overseas temporary migration results in a wage premium upon return, even after controlling for the various potential selection biases. However, the estimates underscore the significance of controlling for both emigration and return migration selections. Ignoring the double selectivity in migration would overestimate the impact of return migration on the wage premium of returnees, as migrants are positively selected relative to non-migrants, but returnees are negatively selected among migrants.     

Is Maternal and Child Health Service use a Causal Gateway to Subsequent Contraceptive use?: A Multi-Country Study

The purpose of this study is to examine the relationship between MCH service utilization and contraceptive use in five countries: Bolivia, Guatemala, Indonesia, Morocco, and Tanzania. The analysis is carried out at the level of the individual woman, with contraceptive-use status modeled as a function of: (1) the availability, quality, and packaging of MCH and family planning services; (2) community- and individual-level determinants of health service and contraceptive use; and (3) intensity of prior MCH service use. Data for the analysis comes from DHS data on women of reproductive age linked with data from service-availability surveys. We use full-information, maximum-likelihood regression techniques to control for the effects of unobserved heterogeneity that might otherwise bias our estimates. In three of the five countries (Morocco, Guatemala, and Indonesia) the results of the analysis suggest that the intensity of MCH service use is positively associated with subsequent contraceptive use among women, even after controlling for observed and unobserved individual- and community-level factors. This result lends support to the proposition that, at least in the context of these three countries, the intensity of MCH service per se use does have a “causal” impact on subsequent contraceptive use, even after controlling for factors that “predispose” sample women to use health care services.     

Two Population-Environment Regimes in the Great Plains of the United States, 1930–1990

This paper analyzes factors that affect net migration rates in counties in the U.S. Great Plains between 1930 and 1990, emphasizing the roles of weather (especially drought), environmental amenities, employment, and population, making use of a rich county-level data set. Using a pooled time series model the paper shows that environment is important in population processes, with weather and agricultural change more important in the 1930s and 1940s, and environmental amenities more important in later time periods. The paper provides important insights into how environmental impacts on migration might change over time, and how those changes might be measured.